Simms, Lillian M., author
Delmar Publisher , 1985
Buku Teks
Barrie, Donald S., author
McGraw-Hill, 1978
Buku Teks
Hugh L.Evans M.A.
Sweet and Maxwell, 1997
Buku Teks
Cooper, Robert U., author
Macmillan, 1953
Buku Teks
Cooper, Robert U., author
Macmillan, 1952
Buku Teks